1. Field of the Invention
The invention relates to an image display system, including an image display apparatus for displaying an image, the image being dependent on the position and/or orientation of the image display apparatus. The invention also relates to an image guided surgery system.
2. Description of Related Art
An image display system of this kind is known from the article Virtual reality assisted surgery program by R. A. Robb and B. Cameron in Interactive technology and the new paradigm for healthcare (1995) (pp. 309-320).
The user of the known image display system wears the image display apparatus on the head. The image shown to the user by the image display apparatus is dependent notably on the orientation of the head of the user. It is thus achieved that the user sees previously recorded image information while the illusion is created that the user sees said image information directly.
The cited article mentions that such an image display system can be advantageously used for medical diagnosis and surgery. In such an application the image display system shows previously recorded image information of a patient to be examined and/or treated to the user, in this case being the attending physician or surgeon, during the treatment. Such previously recorded image information includes, for example images formed by means of magnetic resonance (MRI) methods or X-ray computer tomography (CT). The user need not observe a separate monitor so as to see the previously recorded image information during the treatment of the patient, but instead of a direct view of the patient the user sees pre-recorded image information which is reproduced in conformity with the viewing direction of the user. It is a drawback of the known image display system that it is not very well possible for the user to see previously recorded image information in combination with a direct view of the patient.